Disorder overview: Phenylketonuria is a genetic disorder that disrupts the metabolism of the amino acid phenylalanine. It's caused by the deficiency of a liver enzyme called phenylalanine hydroxylase. The normal phenylalanine metabolism is blocked, so if eaten the enzyme accumulates in the blood and tissues. This, if left untreated, can result in irreversible mental retardation, neurological abnormalities, seizures, eczema and behavioral problems. [1]

To help with PKU you need to have a low protein diet and even if you have a low protein diet it is hard to survive because you would be very weak.

Less than 200,000 cases in the USA

Symptoms:
  • Delayed mental and social skills
  • Small head
  • Jerking movement in arms or legs

PKU could cause you to become weak because you can't get amino acids throughout the whole body.
https://www.youtube.com/watch?v=a0urPofZiuY
a video on what pku is


See the source image
See the source image


References:
http://web.b.ebscohost.com/src_ic/detail/detail?vid=2&sid=86aa1deb-0abc-4810-bd34-2dc34794be28%40sessionmgr101&bdata=#AN=86194421&db=t6o

https://www.mayoclinic.org/diseases-conditions/phenylketonuria/symptoms-causes/syc-20376302

http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=716